140 BLATTID^, OR COCKROACH TRIBE. 



diffused over temperate climates ; although most of the species 

 are believed to have been originally natives of tropical regions, 

 where only they attain their full development. They are 

 nocturnal in their habits, and active in their movements along 

 the ground ; their powers of flight are usually inconsiderable, 

 the wings being usually small in proportion to the size of their 

 bodies ; and they are extremely voracious, devouring with 

 avidity almost every kind of organised matter. In cold climates 

 the wings are scarcely enough developed, even in the male, to 

 raise the body from the ground; whilst in the female they 

 are almost entirely absent. The species which is commonest 

 in this country, the Blatta orientalis, is so named from its being 

 supposed to have been originally a native of the East Indies; it 

 has, however, been so long domesticated with us, that its time 

 and mode of introduction are uncertain. In common with most 

 other species of Blatta, it ejects a dark-coloured fluid from the 

 mouth, emitting a very disagreeable odour, of which it is dim- 

 cult to get rid, and attaching itself to whatever the insect has 

 crept over. The tropical species are larger and more voracious ; 

 one of them, which attains the breadth of six inches when its 

 wings are expanded, is known in the West Indies by the name 

 of drummer, from the sharp knocking sound which it produces, 

 and which is sometimes kept up through a whole night by 

 several individuals replying to each other; and it is said to 

 attack sleeping persons, and even to devour the extremities of 

 the dead. Notwithstanding the disgusting character which 

 attaches to these insects, on account of their appearance and 

 habits, they present several points of much interest to the 

 Naturalist, especially in regard to their mode of depositing their 

 eggs. Instead of being discharged separately, the eggs are col- 

 lected together and deposited at once, enclosed in a large horny 

 case or capsule (equalling half the abdomen of the female in 

 size), and generally of a more or less oval and flattened form, 

 like a small bean with one edge more flattened than the other 

 (Fig. 363, A). Along this edge there is a slit, from end to end 

 of the capsule ; and the plates which form the edges of this slit 

 are jagged or toothed, fitting closely to each other. The interior 



